The National Marine Fisheries Service said yesterday that it has found "substantial scientific or commercial information" that Caribbean and Indo-Pacific corals may be threatened or endangered. Environmentalists have predicted the corals -- found near Florida, Hawaii and U.S. territories -- could be wiped out by midcentury if the government does not take steps to protect them from warming waters, rising ocean acidity and pollution.

The announcement in yesterday's Federal Register (pdf) launches a formal status review by federal biologists. The fisheries service will also accept public comment before deciding next year on whether to list the corals under the Endangered Species Act.

"The status review is an important step forward in protecting coral reefs, which scientists have warned may be the first worldwide ecosystem to collapse due to global warming," said Miyoko Sakashita, oceans director at the nonprofit Center for Biological Diversity. "Endangered Species Act protection can provide a safety net for corals on the brink of extinction."

The center asked the fisheries service last year to protect corals and threatened to sue the agency last month if it failed to act.

All of the species under consideration have seen population declines of at least 30 percent over 30 years, according to the center.

In the service's finding yesterday, biologists agreed that the coral populations are at risk of collapse without recovery, given the population decline that has occurred already and mounting threats.

If the corals are protected as endangered species, it would be illegal to harm or kill the species. That could open commercial fishers, farmers and all the other industries cited in the petition to federal regulation or lawsuits from environmentalists. A "threatened" listing could be less restrictive. The fisheries service would write regulations to protect the corals.

The government now lists two Atlantic coral species, elkhorn and staghorn, as "threatened" due to disease, warming sea temperatures and hurricane damage.

The center had sought a listing for 83 species, but the government left one out of its proposal. The fisheries service said there was not enough evidence to consider a listing for the ivory tree coral, or Oculina varicosa. The ivory tree coral lives in shallow water from Florida to North Carolina and off Bermuda and the West Indies.